/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import com.android.dx.dex.SizeOf;
import com.android.dx.rop.cst.CstString;
import com.android.dx.rop.type.Prototype;
import com.android.dx.rop.type.StdTypeList;
import com.android.dx.rop.type.Type;
import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.Hex;

/**
 * Representation of a method prototype reference inside a Dalvik file.
 */
public final class ProtoIdItem extends IndexedItem {

	/** {@code non-null;} the wrapped prototype */
	private final Prototype prototype;

	/** {@code non-null;} the short-form of the prototype */
	private final CstString shortForm;

	/**
	 * {@code null-ok;} the list of parameter types or {@code null} if this
	 * prototype has no parameters
	 */
	private TypeListItem parameterTypes;

	/**
	 * Constructs an instance.
	 * 
	 * @param prototype
	 *            {@code non-null;} the constant for the prototype
	 */
	public ProtoIdItem(Prototype prototype) {
		if (prototype == null) {
			throw new NullPointerException("prototype == null");
		}

		this.prototype = prototype;
		this.shortForm = makeShortForm(prototype);

		StdTypeList parameters = prototype.getParameterTypes();
		this.parameterTypes = (parameters.size() == 0) ? null
				: new TypeListItem(parameters);
	}

	/**
	 * Creates the short-form of the given prototype.
	 * 
	 * @param prototype
	 *            {@code non-null;} the prototype
	 * @return {@code non-null;} the short form
	 */
	private static CstString makeShortForm(Prototype prototype) {
		StdTypeList parameters = prototype.getParameterTypes();
		int size = parameters.size();
		StringBuilder sb = new StringBuilder(size + 1);

		sb.append(shortFormCharFor(prototype.getReturnType()));

		for (int i = 0; i < size; i++) {
			sb.append(shortFormCharFor(parameters.getType(i)));
		}

		return new CstString(sb.toString());
	}

	/**
	 * Gets the short-form character for the given type.
	 * 
	 * @param type
	 *            {@code non-null;} the type
	 * @return the corresponding short-form character
	 */
	private static char shortFormCharFor(Type type) {
		char descriptorChar = type.getDescriptor().charAt(0);

		if (descriptorChar == '[') {
			return 'L';
		}

		return descriptorChar;
	}

	/** {@inheritDoc} */
	@Override
	public ItemType itemType() {
		return ItemType.TYPE_PROTO_ID_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public int writeSize() {
		return SizeOf.PROTO_ID_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public void addContents(DexFile file) {
		StringIdsSection stringIds = file.getStringIds();
		TypeIdsSection typeIds = file.getTypeIds();
		MixedItemSection typeLists = file.getTypeLists();

		typeIds.intern(prototype.getReturnType());
		stringIds.intern(shortForm);

		if (parameterTypes != null) {
			parameterTypes = typeLists.intern(parameterTypes);
		}
	}

	/** {@inheritDoc} */
	@Override
	public void writeTo(DexFile file, AnnotatedOutput out) {
		int shortyIdx = file.getStringIds().indexOf(shortForm);
		int returnIdx = file.getTypeIds().indexOf(prototype.getReturnType());
		int paramsOff = OffsettedItem.getAbsoluteOffsetOr0(parameterTypes);

		if (out.annotates()) {
			StringBuilder sb = new StringBuilder();
			sb.append(prototype.getReturnType().toHuman());
			sb.append(" proto(");

			StdTypeList params = prototype.getParameterTypes();
			int size = params.size();

			for (int i = 0; i < size; i++) {
				if (i != 0) {
					sb.append(", ");
				}
				sb.append(params.getType(i).toHuman());
			}

			sb.append(")");
			out.annotate(0, indexString() + ' ' + sb.toString());
			out.annotate(4, "  shorty_idx:      " + Hex.u4(shortyIdx) + " // "
					+ shortForm.toQuoted());
			out.annotate(4, "  return_type_idx: " + Hex.u4(returnIdx) + " // "
					+ prototype.getReturnType().toHuman());
			out.annotate(4, "  parameters_off:  " + Hex.u4(paramsOff));
		}

		out.writeInt(shortyIdx);
		out.writeInt(returnIdx);
		out.writeInt(paramsOff);
	}
}
